Electric elevator.



- No.v 693338.

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ELECTRIC ELEvAToR.-

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THE wams Przns co., PHom.|.mo., WASHINGTON. nA c,

lUNITED "STATES PATENT EFICE.

Nus o. LiNDs'rROM, OF NEW YORK, N. Y., AssIGNOR To ALONZO n. sEE AND WALTER L. TYLER, OE BROOKLYN, NEW YORK.

ELECTRIC ELEVATO R.

SPECIFICATION forming part of Letters Patent No. 693,038, dated February 1 1,1902.

Application filed November 9. 1901. Serial No. 81,665. (Normodel.)

vators, of which the following is a full, clear;Y

and exact description.'

This invention relates to the control of elec-1 y A preferred method of operi ating electric elevators isto provide a coun-V tric elevators.

tei-weightV for the car which is heavier than the car itself, but which may become overbalanced by the weight of the passengers,I since this method reduces the average work` upon the motor. In operating such an elevator it sometimes happens that the counter- Weight lifts the car,- inwhich case the drivingmotor is itself driven and becomes'a generator, sendingcurrentfout to the line, while at other'times the'relative weights may be so adjusted by the number of passengers that the machine acts as a motor to either lift the'car or lift the counterweight. In any case there is no certainmeans ofvindicating to the attendant in the car under what condition the actuating-machine is running at any particular time, and he therefore is not in a position to select what kind of regulating means shall be used in a .given instance to alter the speed of the machine. Forinstance, if-the machine is running as a motor its speed could be reduced by throwing resistance into the circuit; but if the machine happened `to be running as av generator the resistance thrown in would increase its speed.

In slow-speed elevators it is seldom necessary kto Vprovide more than one speed for actuating the machine, as the brake can berelied upon to'graduate a stopV sufficiently to avoid a shock,and accurate stops at landings are .easily accomplished; but in high-speed elevators it is .essential that the speed of the actuating-machine' be reduced before stopping at a landing by some other means than a brake,-as the action of: the brake on a car traveling at a high speed would inflict a serious shock on the car and its load. Further- 1nore,an 'accurate stop at a landing cannot usually be accomplished when a car is run ning at 'high speed without first slowing down to a certain extent. Hence for high-speed overcounterweighted elevators it is desirable to provide means for automaticallycontrolling the speed of the actuating-machine ,regardless of whether it is running as a motor or as a generator and which are under the perfect control of the attendant in the car,

whereby he will ybe able to increase or reduce .speed atwill and without causing the car to 2 moveiiregularly or by shocks and ju mps. To accom plish this object, I have provided an actuating electric machinefor the elevator having two armature-circuits, one of which is the regular working or driving circuit supplied from a suitable source of electricity through a commutator and the other is a closed circuit in which a current is generated whenever vthe machine is driven and which is connected through a second commutator` with an external local circuit containing certain resistsuch an actuating-machine and its resistancesfrom the carand through pneu matic apparatus which responds to the movements of the actuating-handle'in the car and causes a gradual change in speed in exact proportion to the extent of movement of the actuatinghandle. In the accompanying drawings, Figure lis a conventional planv of the complete elevator system; and Fig. 2 .is a similar representation of the starting, stopping, and reversing switch.

A indicates the elevator-car; B, a counterweight heavier than the car, but lighter than the car when it is fully loaded. The cord a,

sustaining the car and counterweight, passes over suitable guide-sheaves to a windingydrum D on the'shaft of or otherwise driven ICO ' the two rheostats.

pendent of each other and represented by the respective comm utators c' and lc The brushes of commutator 'c are indicated by 1 and 2 and those of commutator c" by '3 and 4. The main-supply circuit is indicated by the plus and minus signs. Frein one side of this circuit the wire 5 leads through a make, break, 'and Ireversing switch c to a solenoid S, thence lto the terminals or' rheostat r', thence by wire 6 to the brush 2, through the drivingcircuit of the armature, brush l, wire '7, rheostat R, wire S to the minus main. The second circuit of the armature is a closed short circuit, as follows: from brush 3 by wire 9 to solenoid S', wire 10 to rheostat r, wire 1l to rheostat R', and wire 12 to brush 4t. The core of solenoid S carries a contact-piece s, which-when the solenoid is energized traverses the contacts of rheostat r and cuts the resistance into the short circuit of the motor. The core of solenoid S is similarly connected to a contact s', which when the solenoid is energized sufficiently traverses the contacts of rheostat r and cuts resistance into the main circuit of the motor. It will thus be seen that the current flowing in one of the motorcircuits controls the resistance in the other circuit to a certain extent. The rheostats R and R are arranged with their contacts adjacent to each other, so that they can be controlled by a single traveler r2, attached to rod r3. The traveler carries bridging-'contacts 13 and 14, which pass over` the respective contacts of The connections of the circuit-wires 7 and 8 with the terminals of the rheostat R and those of the wires l1 and 12 with the rheostat R are such that when the traveler rgrises resistance is cut out of the main circuit and cut into the closed circuit. The rod r3 connects with a pivoted lever r4, which in turn connects with another rod f, attached to the end of air-cylinder F. This cylinder contains a fixed piston f, attached to the base f2, so that when pressure s admitted above the piston the cylinder is caused to rise or move instead of the piston. Adjacent to the cylinder and preferably formed in the same casting is an air-chamber g, supplied with compressed air or other fluid by pipe g. This chamber communicates with the upper part of the cylinder through a port g2. 1n the upper part of the chamber g is fitted a piston-valve 7L, which when above the port admits pressure into the cylinder, when opposite the port retains the pressure therein, and when below the port opens communication from the cylinder to the atmosphere through the upper open end of chamber g.

The valve'h is attached to a rod h', adapted to be raised and lowered by the oscillation of a lever t, pvoted at t" and to which said rod is connected. The lever is oscillated by lneans of a roller or lug t2, which it carries and which projects into a groove j in a platej. This groove is made up' of a horizontal portion and two downwardly-inclined end por tions. While thc roller is in a horizontal portons 7a2 and 7c3.

eeacss tion of the groove the valve is held stationary, and when the roller is forced into either of the inclined portions of the groove the valve is raised to admit pressure into the cylinder, and when the roller traverses the inclined portionsof the groove toward the horizontal portion valve 7L is moved below the port and allows the pressure to escape from the cylinder. The roller is caused to traverse the groove by reciprocating the plate j, and this is accomplished from the elevatorcar. The plate is attached to a rod 7c, connected to a double bell-crank 7c. From each end of the bell-crank a cord l leads oversuitable guide-sheaves and around a drum or sheave p in the car. By rotating the drum or wheel p in one direction the bell-crank is caused to tilt and move the rod 7c in a corresponding direction. A reverse movement of the controller p gives a reverse movement of the rod k. The rod 7c also controls a valve device for pneumatically operating the main switches and the' brake. The rod passes through an open-ended cylinder and inside thereof is provided with two tight-fitting pis-- A pipe leads to the middleof the cylinder between the pistons and supplies duid-pressure. Outside and beyond each valve pipes qand Q lead to suitable fluidmotors 0 and 0' for throwing the main re versing-switch e. (Shown in Fig. 2,)

It will be understood that when air is ad*- mitted to the pipe q current will be turned' on at the switch e in the proper direction to start the elevator upward, while when air is admitted to the pipe q current is admitted in the proper direction te start the elevator downward. The two pipes q and q are connected together by a cross-pipe q2, containing a valve-chamber cl3, from which another pipe- Q4 leads olf to a fluid-motor for operating the brake, the latter not being shown, since it forms no part of the present invention.. The

valve-chamber Q3 contains a double valve q?, which when pressure enters the chamber from pipe q moves over and closes pipe q andl allows the air from pipe q to enter pipe q",

and when air enters the chamber from pipe q" the valve is forced over and closes pipe q and allows pressure to enter the brake-pipe from q. Hence the brake is operated when pres-v sure is admitted to either of the pipes q 01 q'.

1n the normal condition of the apparatus with the elevator stationary both pipes q and q are open to the atmosphere, as shown. The

roller t2 is in the horizontal portion of thef groove g', valve h is in front of the port g2, cylinder F is in its lowest position, and the solenoids S and Sl are denergized. In this state let it be assumed that the elevator is to be started upward under such conditions of load and counterweight that the motor must do work. By operating the controllerp in the car the assistant moves the rod 7tto the right. The first result of' this is to admit pressure to the pipe q and to the pipe q", which closes the main switchin the direction to start the car 693,038y p v '53 upward and releases the brake. The motor draws sufficient current from the main circuit to lift the load. If the assistant desires to increase the speed, he will continue the motion of the controller in the same direction. This will cause the roller t2 to enter one of the in.- clined portions of the groove j'which will lift the valve h a distance depending upon the movement ofrod Pressure will'enter cylinder F and it will rise luntil the'port is again closed by coming opposite the valve h in its new position. The upward movement of the cylinder causes traveler r2 to cut out a corresponding portion of theresistance R. Consequently-the meter gets more current and accelerates itsl speed, `-When the motorstarted inthe irst instance, the entire resistance Rwastcut of the closed circuit of the motor, but @was thrown-in bysolenoid S, so that the killing eect of the closed circuit was smalland the vmotor was not required to draw excessive current at starting. When the speed was increased by raising the travelerrthe resistance Rf was cutinto the closed circuit at the same time that the resistance R was cut out of the main circuit. `Consequently an increase of current which would naturallyjoe generated in theclosed circuit .runs onto the isolated contacts at the limit of the rheostat and opens the short circuit,

`which renders it entirely ineffectual. `This increaseof speed can be vmade as gradual as desired by the extent of movement of the valve h. It will be seen thatwhen the valve moves upward a given distance the cylinder follows it to the same distance and there stops,

l and the speed of the machine is increased only to a corresponding extent. A further movement of the valve gives additional speed,

the machine would get up its full speed as rapidly as the construction would allow. This would not be too rapidly for the comfort and safety of the load, becausethe size of the port g2 can be regulated to admit pressure to the cylinder at the proper rate to secure the desired result. Both thevalve hand the cylinder F are weighted, by means of the weights w and w, to steady or retard all movements thereof, and the weight w is sufficient to balance the pressure on the valve.

The solenoid S is wound so that it will no lift its core until some ofthe resistance R is cutout. When it does operatethe' resistanceristhrownintothekilling-circuit. Thus the killing-circuit under this condition will be rendered less effective and the motor will start the load easily.

The operation so far described relates to the condition when the motor docs work either in either by the maximum-loaded elevator coming downl or the minimum load going up. When the circuit is closed to start-the elevator, the brake is at the same time released, as

before, whereupon the counterweight or the load drives the machine as a dynamo. At

the'start the closed circuit of the machine contains no resistance, and in consequence the speed of the machine is retarded by the rapid building up of current in the short circuit. The speed at thestart is therefore normal or thesame as vwhen the machine starts under a load. To increase the speed, the rod Za is moved farther in the same direction, as before, and the traveler rises, throwingresistance` R into the closed circuit, cutting down the current therein, and permitting the machine to bedriven faster. The speed can thus be increased by degrees in the same manner as before, and the corresponding decrease of speed is accomplished by the reverse movement of the control". In starting up the machine under its driven condition all of the resistance R is inthe main circuit, and the resistance r is immediately cut in bythe heavy current generated in the closed circuit and acting on solenoid S. Hen-ce a gradual start is assured because the motor receives little, if any, current from the main circuit; but as the traveler r2 moves upward the speed isincreased both bythe removal of resistance R andthe insertion of R until the` highest speed is reached, when the traveler arri-ves at the top of the row of contacts and opens the closed circuit by passing onto the isolated contacts shown. In this system of control, where the two circuits are worked against each other,a very smooth-running electric elevator .is obtained, the motion being more nearly like that of the hydraulic elevator than has been possible heretofore. Theaction ofthe pneumatic devices mate- IOO IIO

ri-ally aids in this smoothness of operation v opposition to each other, a rheostat in each circuit and means for simultaneously throwing one rheostat out of its circuit and the other into its circuit, substantially as described.

3. In an electric elevator, an actuating-machine having two armature-circuits acting -in iii"- opposition to each other, a rheostat in each circuit and means in the elevator-car for simultaneously throwing one rheostat out of its circuit and the other into its circuit, substantially as described.

4. In an electric elevator, an actuating-machine having a main working circuit and a second circuit in which a current is generated by the rotation of the machine, in combination with means in the elevator-car for controlling the current generated in thesecond circuit, substantially as described.

5. In an electric elevator, an actuating-machine having two armature-circuits acting in opposition to each other, a rheostat for each circuit and means whereby current flowing in one circuit will throw one of the rheostats into the other circuit, substantially as described. Y

6. In an electric elevator, an actuating-machine having two armature-circuits acting in opposition to each other, a rheostat for each circuit and means whereby current owing in one circuit will throw 011e of the rheostats into the other circuit, in combination with a second resistance for each circuit under control from the elevator-car.

'7. In an electric elevator, an actuating-machine having two armature-circuits acting in opposition to each other, a rheostat for each circuit and means whereby current flowing in one circuit will throw one of the rheostats into the other circuit, in combination with a second resistance for each circuit, and means in the elevatorcar for simultaneously cutting out one of the second resistances and cutting in the other, substantially as described.

8. In an electric elevator, the combination of an electric actuating-machine, a controlling-rheostat therefor, a fluid-motor adapted to actuate the rheostat, a valve for the motor actuated from the elevator-car, and means whereby the stroke of the motor will correspend to the stroke of the valve.

9. In an electric elevator, the combination of a Huid-motor, a valve therefor having a movement variable at will from the elevatorcar, a movable part o'f said motor having a stroke equal and corresponding to that of the valve, a rheostat for an actuating-machine controlled by said motor, and an actuatingmachine, substantially as described.

10. In an electric elevator, an actuating-machine having two armature-circuits actingin opposition to each other, a rheostat for each circuit, and an electromagnet in each circuit controlling the rheostat for the other circuit.

1l. In an electric elevator, the combination of the car,-acounterweightoverbalancing the car, an actuating -machine having a main circuit and a local short circuit opposing the main circuit, resistances in each circuit and means for con trolling the resistances from the car, substantially as described.

In witness whereof I subscribe my signature in presence of two Witnesses.

, NILS O. LINDSTROM.

Witnesses:

WM. A. RosnNBAUM, FRANK S. OBER. 

